Wrist-motion rotary hand-tool



July 12, 1955 w. E. KNIGHT, JR 2,712,765

WRIST-MOTION ROTARY HAND-TOOL Filed June 26, 1951 2 Sheets-Sheet l 5' 0 INlfENTOR: a F1 lBylulam EhKmght, Jr. I I X 57 AH-orne July 12, 1955 w. E. KNIGHT, JR 2,712,765

WRIST-MOTION ROTARY HAND-TOOL Filed June 26, 1951 2 Sheets-Sheet 2 INVENTORI Wi1l13m E. Knight, Jr.

BY Q

ATTORNEY Patented July 12, 1955 2,712,765 4 WRIST-MOTION ROTARY HAND-TOOL William E. Knight, Jr., Nashville, Tenn. Application June 26, 1951, Serial No. 233,587 3 Claims. (Cl. 81-583) This invention relates to a wrist-motion rotary handtool, and more particularly to one in which by an easy manipulation the parts may be shifted from a high-speed low-torque arrangement into a high-torqueapplying relationship.

It is accordingly an object of the invention to provide a hand-tool which has the advantages of power-driven rotary hand-tools (speed and low worker fatigue) without the weight and high-cost disadvantages thereof.

It is another object to provide a rotary hand-powered tool which is admirably adapted for high-speed assemblyline production by reason of its light weight and its design for efiicient and low-fatigue use of the fore-arm muscles of the user.

It is a further object to design a rotary hand-tool that is easy to understand, to operate and to service.

It is a still further object to provide a rotary handtool that is efiective, durable and economical of manufacture. 3

These and other objects and advantages of the invention will become apparent as the description proceeds.

Detailed description In the drawings, in which like reference characters designate like parts thruout the several figures:

Fig. 1 is a side elevational view of a preferred form of the rotary hand-tool;

Fig. 2 is a detailed axial cross-section of the bearing and clutch portion of the tool of Fig. 1;

Fig. 3 is an enlarged detailed cross-sectional view taken on the line 33 of Fig. 1;

Fig. 4 is an elevational view of a screw-driver tip usable with the tool of Fig. 1;

Fig. 5 is a perspective view of the more conventional type of screw-driver tip;

Fig. 6 is a perspective view of a tap tip;

ig. 7 is a perspective view of a reamer tip;

Fig. 8 is an elevational view of a drill-chuck tip;

Fig. 9 is an elevational view of a ratchet-wrench modification of the invention;

Fig. 10 is a detailed view showing the hinge joint of Fig. 9 in its high-torque position;

Fig. 11 is a detailed view showing the hinge joint of Fig. 9 in its folded or storage position;

Fig. 12 is an end view of a removable socket for the wrench of Fig. 9; and

Fig. 13 is a side view of the socket of Fig. 12.

With reference now to the drawings, Fig. l discloses a pistol-grip form of the invention, in which 1 designates the hand-grip member. The member 1 may be formed of metal, wood or composition materials and is preferably made in two bilaterally symmetrical halfshells connected by two or more screws or rivets 3.. Mounted in the upper part of a bearing member 5 (Figs. 1 and 2) fastened to one of the half-shells of the grip 1, as by screws 7 entering holes 8 in ears 10. Additional holes 9 are provided so that the angle of the bearing member 5 may be varied forwardly at 11b to form the rotational-force-transrnitting tool-tip or tool-tip holder. The tool-tip holder 1112 has a squared or non-circular cross-section and may be provided with a detent ball 13, or the like, to assist in holding work-engaging tips thereon.

Figs. 4, 5, 6, 7 and 8 show a few of the many types of tips usable with the tool of Fig. 1; they are, respeccross-kerf screw-driver, conventional screwdriver, tap, reamer and drill-holding chuck.

The length and orientation of the grip member and the sections of the shaft are designed so that the axis of rotation A of the tool-tip coincides approximately with that of the fore-arm of the user so that a natural and should be long wrist, but should not be so long as to require an excessive or unnatural and fatiguing flexing thereof.

The shaft 11 is mounted for slight longitudinal or axial displacement in the bore of the bearing member 5, being yieldingly urged outwardly thereof by a coiled spring 15 to the position shown in Figs. 1 and 2,

shaft end and the spring bearing.

The shaft 11 is enlarged at 19 which may have gear-like teeth 21. The adjacent end of the bearing member 5 also may have mating teeth 23, so that upon a spring-compressing forward thrust of the grip member, the teeth will engage to lock the shaft 11 against rotation in the grip member 1, so that a high-torque force may be applied, as for example, to produce the last-turn tightening of a screw driven quickly by the low-torque motion.

In some operations, however, like drilling or reaming, it may be desirable to apply considerable axial force while still using the high-speed wrist motion (that is, without engaging the clutch teeth). For such operations, there is provided a locking device (Fig. 3) for preventing the clutch-engaging axial movement of the shaft 11 in the bearing member 5. This locking device comprises a U-shaped member formed preferably of a squared rod so as to present flat bearing surfaces for engagement with mating thrust-bearing surfaces formed by necking down the shaft 11 at 27.

The U-shaped member 25 passes thru two sets of alined holes 10 in the walls of the grip member 1. To wall 1b may be attached a spring-detent means 29 engageable in depressions 31 to hold the locking member in either of its two functional positions, of which the full-line position of Fig. 3 is the locking position. The dottedline position brings the enlarged circular opening 33 into coaxial alinement with the shaft so that the latter may pass freely therethru for a normal clutching action.

Figs. 9l2 disclose a socket-wrench modification of the invention. Numeral 41 designates a conventional ratchet-type head, which carries the usual squared socketentering shaft 44. Shaft 44 enters the conventional base socket 45 (Fig. 13) of the interchangeable various-sized socket-wrench elements of Figs. 12 and 13. Part 47 is a conventional ratchet-Wrench-reversing or disabling control-arm.

One end of the wrench head 41 is provided with two parallel cars 49 having alined bores therethru for receiving an axle-forming pin 51. Pin 51 lies tangentially relatively to a circle defined by its mid-point in rotating about the axis B of the shaft 44. Snugly embraced by to provide a clutch disk,

the ears 49 is a cam-forming head member 53. The head member 53 has three flat surfaces engageabie by 5. felitively strong leaf spring 55 to hold the head, and the handle 57 carried thereby, in any one of the three'pos i tions shown in Figs. 9, l0 and 11. The handle 57 comprises a shaft 59 rigidly attached to the head member 53,a grip part 61 freely revolvable thereon, and an end cap 63 for holding the grip part 61 against endwis'e displacement on the shaft 59. i

Fig. 9 illustrates the normal-use positions of the parts, in which wrist motion will apply a relatively high-speed but low-torque rotational force to a socket-wrench or the like. For a tightening or high-torque operation, the handle 57 is swung upwardly to the position of Fig. 10 (dotted line position 57a in Fig. 9). e

Fig. ll shows the folded or storage positions of the parts.

It is to be understood that many changes can be made in the size and construction of the parts without departing from the spirit of the invention, appended claims. 7

Having thus described my invention, what I claim as novel and desire to secure by Letters Patent of the United States is:

l. A wrist-motion rotary hand-tool, rotary means for applying rotational force to a work piece, said means having a Centrally located of rotation-, a laterally extending torque-applying means attached to said rotary means for rotating the latter; an elongated hand-grip member having its index-finger end adjacent the outer end of said torque-applying means and extending rearwardly and convergingly toward. the aids of said rotary means; means, including a pair of relatively movable mating parts, for connecting said hand-grip member to said torque-applying means, one of said pair of parts being connected to said hand-grip member and the other being connected to said torquea plying means; one of said pair consisting of a shaft as defined by the 4 com rising:

having an axis thru said hand-grip member and about 1112111611 the lattei' is adapted to "rotate during a normally high-speed low-torque wrist-motion rotation of said handgrip member about the axis of said rotary means; said relatively movable parts having selectively engageable portions movable into interlocking engagement by a movement of said hand-grip member away from said axis of rotation, whereby a high-torque rotational force may be applied to said rotary means thru said hand-grip member.

2. A wrist-'mo'tion rotary hand-tool according to claim 1 and in which said mating parts comprise, first and second clutch parts respectively connected to said handgrip member and '10 said to rque=applying means and c0- axially surrounding said shaft, said clutch parts being relatively movable along the axis of said shaft by a forward pressure on saidhand-grip member to engage said clutch parts andthus lock thehand-grip member to the terqueapplying means agaiss relative rotation. 3. Wrist-motion rotary hand-tool according to claim 2 and in i ch said hand=gtip member carries a selectively movable stop-means for preventing or permitting engagement of said clutch parts.

'Rferenesfitea in the file 0111115 patent UNITED STATES PATENTS 

